Valve member for two-stroke-cycle internal-combustion engines



ch 8 1927 H. SCHNEIDER STROKE CYCLE INTERNAL COMBUSTION ENGINES VALVE MEMBER FOR TWO Filed Jan. 5. 1924 Patented Feb. 8, 1927. i

UNITED STATES PATENT OFFICE.

HEINRICH SCHNEIDER, OF ILLN AU, SWITZERLAND.

VALVEMEMBER FOR TWO-STROKE-CYCLE INTERNAL-COMBITSTION ENGINES. Application filed January 3, 1924, Serial No. 684,179, and in Germany January 8, 1923.

The present invention relates to a valve ed on the accompanying drawings, in which: or controlling member for, two-stroke cycle Fig. l is a vertical section through the upinternal combustion en ines, and which conper part of a vertical internal combustion sists of one or more sli e valves inthe shape engine in which the 'controlling member acof hollow cylinders having flaps pressed cording to the present invention is utilized, against seats or tightening faces by a fluid Fig. 2 is a horizontal section along line pressure, whereas passage areas 'to be con- "II-II of-Fig. 1, trolled are uncovered by a displacement of Fig. 3 is a perspective view of the control- :the controlling member. The present conling member,

In trolling member is particularly suitable for Fig. 4is a modified design of the member machines with which an equalization of in a horizontal section, and 1 pr'essureor a relief of the controlling mem- Fig. 5 shows a general arrangementiof the ber from the pressure occurs during the periinternal combustion engine, part of which is od in which it is displaced or moved and illustrated in Fig. 1.

[5 with which .the member remains stationary Fig. 3 illustrates a valve 1 shaped as a when the pressure act on it as is for in-. hollow cylinderprovided in itslower part stance the case with valve members con with flaps 3 uniformly spaced around the ling the admission of scavenging air with circumference, the flaps are obtained by slottwo-stroke cycle internal combustion engines. ting this lower part of Hm valve hey Flaps. similar to those of the elastic flap are resilient in a radial direction. The flaps valves are, for instance, obtained by the pro- 3 cover, in the manner of flaps of flap valves, vision of slots or notches on the cylindrical the ports (shown at 4.- in dotted lines) the controlling part of the valve. The present passage through which has to be controlled, controlling member differs from theknown the parts adjacent the edges of the flaps bespring loaded flaps of flap valves inasmuch mg pressed by an internal pressure on the as with the former the passage area is unrectangular seats enclosing the ports. The covered b a' dis lacement of the valve cylindrical valve is guided 'on its inner and whereas-with the ap valves this is effected outer side and little clearance between the by a lifting movement of the flap, the man- Valve and the .guidances being provided so ner of effecting the tightening by the flap that the deflection of the flaps on being being pressed against a support or seat is pressed against the seats for efi'ecting the common to both types of valves This divitightening is very small. sion in the manner of working of the valve, Fig. 4 represents a cross-section of a modihowever, permitsthe adoption of very large fied valve consisting of two cylindrical passage areas. Y bushes one arranged inside the other and A Very essential feature of the controllingv provided with flaps which are staggered. member according to the present invention This valve presents a. greater elasticity, inconsists in the fact that the unloaded flaps creased tightening qualities and strength. scrape clean the seat with which the mem-- InFig. 1 the upper part of the working ber cooperates on moving downwards and cy m r O YO- cy rn l mthat the inner side of the flaps on account bustion engine is shown in WhlCh a valve 1 of the latter being pressed in a radial di accordin .to the present invention serves to rection by the pressure of the scavenging control tie adIIllSSlOIl of the scaveng1ng air, air are scraped clean by the art of the and Fig. 2 shows a cross-section of the valve cylinder head projecting into t e cylindriand the admlssion ports. Y cal controlling member. A further feature The piston 5 is illustrated in its lowermost consists in the fact that the valve in its positiomthee haust p rts are uncovered and raised. position is effectively cooled by the th 1 S y means of h level inner and outer guidance and when in mo- 7, double cam 8 and stirrup 9 into its uption by the scavenging air flowing past the permost position, so that scavenging air is 5 valve. This featurepermits the utilization permitted to enter into the combu i P of the valve in'internal combustion engines from the annular chamber 10 through the in which high temperatures occur. ports 11 and to flow through the cylinder Constructional examples of the subject and to leave the latter, by the exhaust ports 6. matter of the present invention are 'illustrat- The valve 1 is guided in the cylinder cover and by the part 16 of the latter projecting into the interior of the valve 1 and is packed against the combustion space by means of packing rings 17. .In thls raised position the .valve 1 is cooled by the inner and outer guidance. In the lowermost posito bear on the combustion engine.

chine by means of bevel the slots in the valve come bridge parts 12 separating the ports 11 and the flaps are pressed tight against the cylindrical facing 20,-in which the ports end, by the internal pressure.

Fig. 5 shows diagrammatically the general arrangement of a two-stroke cycle internal The cam shaft 21 is driven from the crank shaft 22 of'the magears 23,24, upright shaft 25 and bevel gears 26, 27 for instance arranged at both ends of the machine.

The slots 2 are preferably very narrow so that the hot combustion gases have only a very. limited cross-sectional area through which a possible escape may occur. To this end the width of the milled slots may be reduced to a minimum amount by chasing or swaging the material previous to finishing tion of the valve the valve to narrow the slots.

The present valve is particularly adapted for use as the member controlling the admission of scavenging air with high-speed two-stroke cycle internal combustion engines, because the movement of the valve occurs when the-latter is nearly completely relieved of the pressure and as an effective cooling of the valve is obtained, whereas during the compressionycombustion and expansion periods the flaps are pressed tight against their seats in the closed position of the valve. Thevalve may be built very light so that the forces for moving the valve may be kept small and. large passage areas may be controlled by the valve.

The present valve'may be designed as a longitudinally movable slide valve or as a rotary valve.

smaller diameter than ports and means I claim:

, 1. In a two stroke cycle internal combustion enginaa reciprocable sleeve-valve of the'piston of such engine arranged in the cylinder head for controlling theadmission of scavenging air, resilient flaps at the lower end of said valve, integral therewith and obtained by slitting the-lower end portion of the valve, a cylindrical facingin thecylinder head provided with closely arranged air inlet ports arranged around said facing, narrow bridge parts alternating with said ports to obtain a maximum port area, the lower portion of said valve controlling said ports, the resiliency of said flaps permitting them to be pressed against said facing to close said to reciprocate said valve during the scavening period and hold it stationary during all other periods.

. 2. In a two stroke cycle internal combustion engine a reciprocable sleeve-valve of smaller diameter than the piston of such engine, arranged in the cylinder head for controlling the admission of scavenging air, resilient flaps at the lower end of said valve, integral therewith, the lower end portion of the, valve, the slits between said flaps being narrowed by swaging ,the lon itudinal edges of the flaps, a cylindrical facing in the cylinder head, provided with closely arranged air inlet ports arranged around said facing, narrow bridge ports alternating with said ports to obtain a maximum port area, the lower portion of said valve controlling said ports, the resiliency of said flaps permitting them to be pressed against said facing to close said orts and means to reciprocate said valve uringthe'scavenging period and hold it stationary during all other periods.

In testimony whereof I aflix my signature.

HEINRICH SCHNEIDER.

and obtained by slitting 

